/**
 * Software License, Version 1.0
 * 
 * Copyright 2003 The Trustees of Indiana University.  All rights reserved.
 * 
 *
 *Redistribution and use in source and binary forms, with or without 
 *modification, are permitted provided that the following conditions are met:
 *
 *1) All redistributions of source code must retain the above copyright notice,
 * the list of authors in the original source code, this list of conditions and
 * the disclaimer listed in this license;
 *2) All redistributions in binary form must reproduce the above copyright 
 * notice, this list of conditions and the disclaimer listed in this license in
 * the documentation and/or other materials provided with the distribution;
 *3) Any documentation included with all redistributions must include the 
 * following acknowledgement:
 *
 *"This product includes software developed by the Community Grids Lab. For 
 * further information contact the Community Grids Lab at 
 * http://communitygrids.iu.edu/."
 *
 * Alternatively, this acknowledgement may appear in the software itself, and 
 * wherever such third-party acknowledgments normally appear.
 * 
 *4) The name Indiana University or Community Grids Lab or NaradaBrokering, 
 * shall not be used to endorse or promote products derived from this software 
 * without prior written permission from Indiana University.  For written 
 * permission, please contact the Advanced Research and Technology Institute 
 * ("ARTI") at 351 West 10th Street, Indianapolis, Indiana 46202.
 *5) Products derived from this software may not be called NaradaBrokering, 
 * nor may Indiana University or Community Grids Lab or NaradaBrokering appear
 * in their name, without prior written permission of ARTI.
 * 
 *
 * Indiana University provides no reassurances that the source code provided 
 * does not infringe the patent or any other intellectual property rights of 
 * any other entity.  Indiana University disclaims any liability to any 
 * recipient for claims brought by any other entity based on infringement of 
 * intellectual property rights or otherwise.  
 *
 *LICENSEE UNDERSTANDS THAT SOFTWARE IS PROVIDED "AS IS" FOR WHICH NO 
 *WARRANTIES AS TO CAPABILITIES OR ACCURACY ARE MADE. INDIANA UNIVERSITY GIVES
 *NO WARRANTIES AND MAKES NO REPRESENTATION THAT SOFTWARE IS FREE OF 
 *INFRINGEMENT OF THIRD PARTY PATENT, COPYRIGHT, OR OTHER PROPRIETARY RIGHTS. 
 *INDIANA UNIVERSITY MAKES NO WARRANTIES THAT SOFTWARE IS FREE FROM "BUGS", 
 *"VIRUSES", "TROJAN HORSES", "TRAP DOORS", "WORMS", OR OTHER HARMFUL CODE.  
 *LICENSEE ASSUMES THE ENTIRE RISK AS TO THE PERFORMANCE OF SOFTWARE AND/OR 
 *ASSOCIATED MATERIALS, AND TO THE PERFORMANCE AND VALIDITY OF INFORMATION 
 *GENERATED USING SOFTWARE.
 */
package cgl.narada.service.compression;

import java.util.Properties;
import java.util.zip.DataFormatException;
import java.util.zip.Deflater;
import java.util.zip.Inflater;

import cgl.narada.event.NBEvent;
import cgl.narada.event.impl.NBEventGenerator;
import cgl.narada.service.ServiceException;
import cgl.narada.service.qos.impl.QosServiceImpl;

/** This class is responsible for compressing events. Based on the specified
    compression constraints.
    
    @author Shrideep Pallickara
    $Date$
    $Revision$
*/

public class CompressionService {
  private String defaultAlgo = "zlib";

  private QosServiceImpl qosServiceImpl;
  private NBEventGenerator nbEventGenerator;
  private String moduleName = "CompressionService: ";

  /** This is to be used for testing purposes only */
  protected CompressionService() {
    this.nbEventGenerator = new NBEventGenerator();
  }

  public CompressionService(QosServiceImpl qosServiceImpl) {
   this.qosServiceImpl = qosServiceImpl;
   this.nbEventGenerator = qosServiceImpl.getEventGenerator();
  }
  
  
  public void 
  compressEvent(NBEvent nbEvent, Properties compressionProperties,
		boolean isPayloadCompressionFinalStep) 
    throws ServiceException {
    String compressionAlgo = 
      compressionProperties.getProperty("compressionAlgo"); 
    
    if (compressionAlgo == null) {
      System.out.println(moduleName + "Compression algo was not specified, "+
			 "will use [" + defaultAlgo +"]");
      compressionAlgo = defaultAlgo;
    }
    
    if (compressionAlgo != "zlib") {
      System.out.println(moduleName + "Libraries for specified compression " +
			 "algo [" +  compressionAlgo + "] not available " +
			 "will use [" + defaultAlgo +"]");
      compressionAlgo = defaultAlgo;
    }
    
    byte[] contentPayload = nbEvent.getContentPayload();
    byte[] compressedPayload = null;
    if (compressionAlgo == "zlib") {
      compressedPayload = compressPayload(contentPayload);
    }
    
    nbEventGenerator.updateCompressionInformation(nbEvent, compressionAlgo,
						  contentPayload.length,
						  isPayloadCompressionFinalStep,
						  compressedPayload);
    
  }



  
  public byte[] compressPayload(byte[] payload) {
    Deflater compresser = new Deflater();
    compresser.setInput(payload);
    compresser.finish();
    int payloadLength = payload.length;
    System.out.println("Payload length=" + payloadLength);
    
    byte[] output = new byte[payloadLength];
    int compressedDataLength = compresser.deflate(output);
    System.out.println("compressedDataLength=" + compressedDataLength);

    if (compressedDataLength == payloadLength) {
      return payload;
    }
    
    byte[] compressedBytes = new byte[compressedDataLength];
    System.arraycopy(output, 0, compressedBytes, 0, compressedDataLength);
    return compressedBytes;
    
  }


  public void decompressPayload(byte[] compressedPayload, int originalLength) {
    Inflater decompresser = new Inflater();
    decompresser.setInput(compressedPayload);
    byte[] originalPayload = new byte[originalLength];
    try { 
      int resultLength = decompresser.inflate(originalPayload);
      System.out.println("Result Length = " + resultLength);
      System.out.println(new String(originalPayload));
    } catch (DataFormatException dfe) {
      System.out.println(dfe);
    }
  }

  public static void main(String[] args) {
    CompressionService compress = new CompressionService();
    
    String testString = "1222222222222222222223455555555555555566667891045";
    byte[] compressedBytes = compress.compressPayload(testString.getBytes());
    
    compress.decompressPayload(compressedBytes, testString.length());
  }

}
